Interlocking operating mechanism



1966 u. F. CARTER ETAL 26,113

INTERLOCKING OPERATING MECHANISM Original Filed May 17 1962 UnitedStates Patent 26,113 INTERLOCKING OPERATING MECHANISM Uriel F. Carter,Wauwatosa, and Arthur F. Kolb, Mequon,

Wis., assignors to Cutler-Hammer, Inc., Milwaukee,

Wis., a corporation of Delaware Original No. 3,196,227, dated July 20,1965, Ser. No.

195,571, May 17, 1962. Application for reissue Mar.

3, 1966, Ser. No. 534,285

12 Claims. (Cl. 200-50) Matter enclosed in heavy brackets I: appears inthe original patent but forms no part of this reissue specification;matter printed in italics indicates the additions made by reissue.

This invention relates to mechanical linkage devices designed toalternately operate two mechanical devices. More particulary thisinvention relates to interlocking mechanisms to alternately actuate twotoggle operated electrical switches.

It is an object of the invention to provide an interlocking mechanism ofeconomical construction to alternately operate two separate mechanicaldevices.

A more specific object of the invention is to provide an interlockingrotary operator to alternately actuate two lever or toggle operatedmotor starters.

A further specific object of the invention is to provide a knob operatedinterlocking operating mechanism for two manually actuated circuitbreakers, one of which has overload protection suitable for a high motorspeed and the other has overload protection suitable for a low motorspeed.

Other objects and advantages of the invention will hereinafter appear.

While the device hereinafter described is effectively adapted to fulfillthe objects stated, it is to be understood that we do not intend toconfine our invention to the particular preferred embodiment of operatoror switch disclosed since it is susceptible of various modificationswithout departing from the scope of the appended claims.

In the accompanying drawings:

FIGURE 1 is a front view of a two speed manual operated electric motorstarter embodying the present invention;

FIG. 2 is a sectional view taken on line 2-2 of FIG. 1;

FIG. 3 is a front view with the cover of the starter removed;

FIG. 4 is a view similar to FIG. 3 but with the operating mechanismrotated to its opposite position; and

FIG. 5 is a rear view of the interlocking and operating mechanism in itsintermediate off position and removed from the starter assembly.

The device illustrated in the drawings and described herein comprises aninterlocking operator and two toggle operated motor starters or circuitbreakers mounted within an enclosure and is adapted for use as a twospeed motor starter. The interlocking operator can, of course, beemployed in assemblies incorporating other types of switches ormechanical devices and is not limited in purpose to the control ofmotors.

The enclosure of the device comprises a rectangular box-like case 2 ofsheet metal construction and a cover 4 fitting over the open front ofcase 2. Conduit knockouts (not shown) are provided in both the top andbottom of the case 2 for entry of electrical wiring. Two

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opposed pairs of mounting brackets 6 are welded to the interior surfaceof the case near the forward edges of the top and bottom. In the centerof cover 4 there is an aperture through which passes the flattened endof operating shaft 8. Above and below this central aperture there areapertures to accommodate screws 10 which fasten cover 4 to mountingplate 12. A reference mark 14 is inscribed in the front surface of thecover 4. An operating knob 16 tightly engages the protruding flattenedend of shaft 8. The words high, low and off inscribed near the peripheryof rotatable knob 16 visually indicate the operating position of theinterior mechanism, since in each of the three stable positions of themechanism. the respective descriptive word becomes alined with thereference mark 14.

Inside the enclosure there are mounted two toggle operated circuitbreakers 18 equipped with thermal overload trip mechanisms, theconstruction and operation of which are shown and described in KolbPatent No. 2,813,951. Each of these circuit breakers 18 has two mountingstrips 18a (FIG. 2) and a toggle operating lever 18b having an off" andon position. As the circuit breakers are oriented in the drawing, theupward position of operating lever 18b is the on position and thedownward position is the off position. These circuit breakers 18 areattached, together with mounting plate 12, to mounting brackets 6 withinthe case 2 by screws 20 which pass through the slots within offsetmounting tabs 22 of mounting plate 12, through apertures within mountingstrips 18a of circuit breakers 18, and through mounting brackets 6 (FIG.2). A speed nut 24 attached to bracket 6 fastens the inner end of screw20.

The mounting plate 12 is generally rectangular with mounting tabs 22projecting from the top and bottom. Two pair of oppositely positionedmounting tabs 22 are offset to the rear of the plane of the centralportion of plate 12 and are used to fasten plate 12 and the attachedoperating mechanism to mounting brackets 6. Between tabs 22, there aretwo cover mounting brackets 26 having threaded apertures to accommodatescrews 10 and having outer edges bent forwardly (FIG. 2) to hold cover 4a proper distance from the operating mechanism. In the central portionof plate 12 there are two parallel rectangular apertures 28 to allow themovement of operating levers 18b. Shaft 8 passes through and isjournaled within a round aperture in the center of plate 12.

A square cam member 30 with slightly rounded corners is formed on shaft8 immediately forward of plate 12. A substantially U-shaped cam follower32 cooperates with cam 30 and is biased into engagement therewith bycompression spring 34 which is positioned between the upwardly pointinglegs of U-shaped cam follower 32. Cam follower 32 slides verticallywithin a generally rectangular space between plate 12 and followerguiding channel 36, the edge portions 36a of which are welded to plate12. The upper end of spring 34 is retained by a small spring retainertab 36b formed in the upper surface of channel 36. The cam 30 andfollower 32 furnish yieldable position indexing means for shaft 8 andprovide the proper tactile feel to the mechanism.

Behind plate 12, there is a flat combination crank and interlock lever40 non-rotatably attached at its center to the end of shaft 8 (FIG.Lever 40 has a truncated tapered end [and 40a] 40a and a roundedopposite end at which there is welded a rearward facing headed pin 42.This headed pin or crank pin 42 passes through and slides within slot46a in the fiat drive lever 46 which is directly behind crank-interlocklever 40. The head of crank pin 42 serves to retain drive lever 46 onpin 42 by engaging the rear surface of drive lever 46. At each end ofdrive lever 46, there are formed rectangular notches 46b to loosely fitover and engage the Operating levers 18b of circuit breakers 18. Asemi-circular recess is formed in the upper edge of drive lever tofacilitate the welding of crank interlock lever 40 to shaft 8. Twoindentations 46c (FIG. 3) on the rear side of lever 46 are the result ofa process in which two small extruded projections 46d (FIGS. 3 and 4)are formed directly oppositely on the front surface of drive lever 46These projections 46d serve as stops in conjunction with crank interlock40. Their function will be more fully explained later.

The operation of mechanism will now be explained. The directions used inthe following explanation, unless otherwise indicated, have reference tothe mechanism as shown in the front views of FIGS. 1, 3 and 4.

With both circuit breakers 18 turned off, both operating levers assumethe lower ofi position and the mechanism appears as illustrated in FIGS.1, 2 and 5. The operating knob 16 is oriented so that the word olf' onthe peripheral flange of knob 16 is alined with index mark 14. Thepressure of cam follower 32 on the edge of cam 30 serves to properlyaline knob 16 and yieldably restrain knob 16 and shaft 8 from undesiredrotation. In the off" condition, the drive lever 46 extendshorizontally, as shown in the rear view of FIG. 5, between the twodepressed operating levers 18b. The crank interlock lever 40 assumes avertical position (FIG. 5) and crank pin 42 is positioned intermediatelyin slot 46a of drive lever 46.

Switching to either the high or low" positions is accomplished byrotation of operating knob 16. In the configuration illustrated,activation of the left circuit breaker 18 is intended to cause a highmotor speed and is equipped with thermal overload protection suitablefor high motor speeds. The right circuit breaker is a similar device butis equipped for low motor speeds. To switch to high speed conditionshown in FIG. 3, knob 16 is rotated clockwise causing crank interlocklever 40 to be similarly rotated. Crank pin 42 at the lower end of lever40 moves leftward in slot 46a and clockwise through a 90 are about shaft8. Drive lever 46 is restrained from horizontal movement by operatinglevers 18. As crank pin 42 moves upwardly, it exerts a force on theupper edge of slot 46a of drive lever 46. Since the notched ends ofdrive lever 46 engage operating levers 18b, an upward force is exertedagainst each of the operating levers 18b. But a greater force is exertedupon the left operating lever during the clockwise movement to the highposition because the distance from headed pin 42 to the left operatinglever is less than the distance to the right operating lever 18b.Consequently the left or high speed circuit breaker is actuated. Theright end of drive lever 46 may move upwardly to some extent during thisprocess depending upon the force required to move the operating lever ofthe right circuit breaker, but it does not move far enough to effectactuation of the snap action mechanism of the right circuit breaker.Upon actuation of the left circuit breaker, the consequent release ofthe force against the left end of drive lever 46 removes pressure oflever 46 against the right operating lever and allows the right lever toreturn to its original off position. It may be said, therefore, that theright end of lever 46 remains substantially at rest during the movementof the left end of lever 46 which causes actuation of the left circuitbreaker. Furthermore, the tapered end 40a of crank interlock lever 40is, at the same time, rotated in a clock wise direction to engage theupper surface of the right operating lever 18b to provide furtherprotection against simultaneous actuation of both circuit breakers 18.

During the rotation to the high" position shown in FIG. 3, cam 30 forcescam follower 32 upwardly, and when the high position is assumed, cam 32is biased downwardly by spring 34 to engage another of the fiat sides ofcam 30 and thereby yieldably index the rotating members in the highposition. Further clockwise rotation is prevented primarily by thecontact of the tapered interlock end 40a of lever 40 with the rightoperating lever 18b, and secondly by the contact of the left projection46d on drive lever 46 against the lower edge of crank lever 40.

To turn the left circuit breaker off, the knob 16 is rotatedcounterclockwise 90 to its original position, returning the mechanism toits original condition. This movement forces crank pin 42 downwardlyagainst the lower edge of slot 46a. Lever 46 is thereby returned to itsoriginal horizontal position and the left operating lever is returned toits off position. Since the right lever 18b is already in its downwardposition, there is no effect on the right or low speed circuit breaker.

The low speed circuit breaker may be similarly actuated bycounterclockwise rotation of knob 16 until the word low on knob 16becomes alined with index mark 14. Crank pin 42 then moves to the rightside of slot 46a forcing the right side of drive lever 46 upwardly. Thetapered end 40a of crank interlock lever 40 simultaneously moves in acounterclockwise direction to contact the left operating lever 18b. Theright operating lever 18b is forced upwardly and the right or low speedcircuit breaker is actuated. The right projection 46d on drive lever 46contacts the lower edge of crank lever 40 to limit rotation and camfollower 32 engages a third of the sides of cam 30. The mechanism thenappears in the low speed condition as illustrated in FIG. 4. A 90rotation of knob 16 will reverse the process and return the mechanism toits original position and turn off the low speed circuit breaker.

The circuit breakers 18 are of the trip-free" thermal overload typewhich, following tripping, may be reset after the overload mechanism hascooled by movement of the operating lever 18b from the on position tothe off position. It can be seen that this operation of resetting eitherof these circuit breakers when used with the illustrated interlock andoperating assembly may be performed by rotation of knob 16 to the offposition.

We claim:

1. In an electrical control device:

(a) a first electrical switch having a first operating member extendingtherefrom;

(b) a second electrical switch having a second operating memberextending therefrom;

(c) a drive member engaging said first operating member and said secondoperating member;

(d) a rotary operating member having first and second actuatingpositions and an intermediate position;

(c) means connecting said rotary member to said drive member to actuatesaid first electrical switch when said rotary member is rotated in afirst direction from said intermediate position and for actuating saidsecond electrical switch when said rotary member is rotated in a seconddirection from said intermediate position whereby said first and secondelectrical switches are alternately and individually actuated;

(f) interlocking means separate from said drive member and driven bysaid rotary member when a switch is actuated for blocking the movementof the operating member of the other of the switches whereby Jsimultaneous actuation of said first and second switches is prevented.

2. The invention as defined in claim 1 together with:

(a) a cam on said rotary member; and

(b) a cam follower biased into engagement with said cam;

(c) the cooperation of said cam and cam follower serving to index saidrotary member.

3. In an operating mechanism for a pair of two position devices havingtoggle operators in combination:

(a) a base member;

(b) an operating shaft rotatably journaled in said member and having anintermediate position and two rotary spaced operating positions onopposite sides of said intermediate position;

(c) a drive member engageable adjacent its opposite ends with saidtoggle operators;

(d) driving connections between said shaft and said drive memberslidably engaging said drive member;

(e) said driving connections, when said shaft is in said intermediateposition, holding both ends of said drive member in a position whereinboth of said toggle operators are both in the first of their twopositions;

(f) and said driving connections, when said shaft is rotated to itsother operating position, sliding toward one end of said drive memberand shifting said one end of said drive member while the other endremains substantially at rest and vice versa.

4. The combination according to claim 3 together with another memberextending from said shaft and rotating in correspondence with said shafttoward whichever end of said drive member is substantially unmoved whensaid shaft is operated to either of its said other operating positionsto hold the operator of the device associated with such end of saiddrive member against movement from the position it is then in.

5. The combination according to claim 3 wherein said drive member isnotched at each end to straddle the operators of said devices.

6. The combination according to claim 3 wherein said driving connectionscomprise a slot in said drive member and a crank fixed to said shaft andhaving a pin in said slot.

7. In an operating mechanism for a first mechanical device having afirst operating means extending therefrom and a second mechanical devicehaving a second operating means extending therefrom;

(a) drive means to extend between and operably engage said first andsecond operating means;

(b) a crank member rotatably journaled at a position between said firstand second mechanical devices;

(c) means on said crank member serving to transmit force to said drivemeans between the portions of said drive means which engage said firstand second operating means;

(d) said means on said crank member being disposed to move, consequentto rotation of said crank member in a first direction, from anintermediate position between said first and second operating meanstoward a first end of said drive [member] means to a first actuatingposition and move with a component of motion transverse with respect toa line between said first and second operating means to actuate saidfirst end of said drive means while the second end of said [crank] drivemeans remains substantially at rest, and said means on said crank memberbeing disposed to move, consequent to rotation of said crank member in asecond direction, from said first actuating position to saidintermediate position to reverse the movement of said drive means andreturn said drive means to its original position;

(e) said means on said crank [means] member further being movable,consequent to rotation of said crank member in a second direction, fromsaid position intermediate said first and second operating means towarda second end of said drive means to a second actuating position and movewith a component of movement transverse with respect to a line betweensaid operating [member] means to actuate said second end of said drivemeans while said first end of said drive means remains substantially atrest, and said means on said crank member being disposed to move,consequent to rotation of said crank member in a first direction fromsaid second actuating position to said intermediate position, to reversethe movement of said drive means and return said drive means to itsoriginal position;

(f) whereby said first mechanical device and said second mechanicaldevice are alternately operated.

8. The invention as defined in claim 7 together with:

(a) interlocking means attached to said crank means and extending in adirection from the crank journal point opposite from said means on saidcrank member for transmitting force to said drive means, saidinterlocking means blocking the path of movement of said secondoperating means when said first operating means is actuated and blockingthe path of movement of said first operating means when said secondoperating means is operated, whereby simultaneous operation of saidfirst and second operating means is prevented.

9. The invention defined in claim 8, together with:

(a) a cam connected to said crank means; and

(b) a cam follower biased into engagement with said cam;

(c) the combination of said cam and said cam follower serving to indexsaid crank means.

10. In an electrical control device:

(a) first and second electrical switches having toggle operators;

(b) supporting means with said first and second switches mounted thereonin side-by-side relation; (c) a crank member journaled between saidfirst and second switches;

(d) a drive lever extending between said first and second switches andthe ends of which engage the respective toggle operators of said firstand second switches;

(e) a slot in said drive lever extending generally longitudinallybetween said ends of said drive lever; and

(f) a crank pin on said crank member which slidably engages said slot insaid drive lever;

(g) said crank pin being movable toward a first end of said drive leverupon rotation of said crank in a first direction from a center positionto displace said first end of said drive lever laterally with respect toa line extending between the ends of said drive lever to actuate saidfirst switch while the second end of said drive lever remainssubstantially at rest; and

(h) said crank pin further being movable toward said second end of saiddrive lever upon rotation of said crank lever in a second direction fromsaid center position to displace said second end of said drive lever toactuate said second switch while said first end of said drive leverremains substantially at rest;

(i) whereby said first and second switches are alternately operated.

11. The invention as defined in claim 10, together with:

(a) an interlocking lever attached to said crank member and extending ina direction opposite said crank pin from the point at which said crankis journaled, said interlocking lever blocking the movement of thetoggle operator of said second switch when said first switch is actuatedand blocking the movement of the toggle operator of said first switchwhen said second switch is actuated;

(b) whereby simultaneous actuation of said first and second switches isprevented.

7 8 12. The invention as defined in claim 11, together with: UNITEDSTATES PATENTS a a Cam i S f membert; f 1,805,375 5/1931 Sampson 74-433a 0 war use 111 0 engage-men W1 Sal 2158657 5/1939 Frank et a] 200*502,961,501 11/1960 Piteo 200-50 (0) the combination of said cam and camfollower 5 serving to index said crank member in its operatingpositions. ROBERT K. SCHAEFER, Primary Examiner.

References Cited by the Examiner BERNARD A. GILHEANY, Examiner.

The following references, cited by the Examiner, are of 10 GINSBURG,148mm"! Examinerrecord in the patented file of this patent or theoriginal patent.

